Light-sensitive silver halide color photographic emulsion containing yellow-forming coupler

ABSTRACT

A COMPOUND FOR THE GENERAL FORMULA   1-(R1-C(=O)-CH(-X)-CONH-),2-Y,5-(R3-OOC-CH(-R2)-OOC-)   BENZENE   WHEREIN R1, R2, R3, X AND Y AS DEFINED IN THE CLAIMS IS FOUND TO BE USEFUL AS A YELLOW COUPLER IN A LIGHT-SENSITIVE SILVER HALIDE EMULSION. THE COMPOUND WHEN USED AS SAID YELLOW COUPLER IS CHARACTERIZED IN THAT IT CAN YIELD A YELLOW DYE IMAGE WITH GOOD STABILITY AGAINST MOISUTRE AND LIGHT ATTACK.

United Smres Patent 3,664,841 Patented May 23, 1972 3,664,841LIGHT-SENSITIVE SILVER HALIDE COLOR PHOTOGRAPHIC EMULSION CONTAIN- INGYELLOW-FORMING COUPLER Masakuni Iwama, Isaburo Inoue, Yutaka Takei,Kenro Sakamoto, and Takaya' Endo, Tokyo, Japan, assignors tIoKonishiroku Photo Industry Co., Ltd., Tokyo,

apan No Drawing. Filed Nov. 28, 1969, Ser. No. 880,954

Int. Cl. G03c 1/40 US. Cl. 96-100 8 Claims ABSTRACT OF THE DISCLOSURE Acompound of the general formula m-oooncomr-Q This invention relates to alight-sensitive color photographic emulsion containing a novel yellowcoupler which is soluble in a high boiling solvent difiicultly misciblewith water.

Heretofore, as couplers used in a light-sensitive color photographicemulsion, there have been known a watersoluble coupler, so-called Agfatype coupler and a socalled protected type coupler which is soluble in ahigh boiling solvent difiicultly miscible with water. In general, adeveloped dye image obtained by the development of the protected typecoupler is more stable than that obtained from the Agfa type coupler tolight, heat, humidity and chemicals. Conventionally known protected typecouplers, however, are not satisfactory because their solubility in ahigh boiling solvent is so poor that they may be readily crystallized inthe emulsion layer. Further, on account of the expensiveness of thestarting material or the complexity of the synthetic procedures, theresulting coupler is of considerably high cost.

On the contrary, it has been known that couplers made from fattymaterials are available at low cost by virtue of mass-produced higherfatty alcohols, higher fatty acids or derivatives thereof. A number ofsuch couplers are, however, poor insolubility in a high boiling solventand liable to crystallize in the emulsion layer. Therefore, extensiveresearch has been made in order to prepare a coupler having highsolubility in a high boiling solvent by using such fatty materials.

For example, the coupler of the formula COOR (wherein X and R have thesame meanings as in Formula I with ethyl 'benzoylacetate. Saidintermediate can be obtained by transesterification of methyl3-aminobenzoate, methyl 3-amino-4-lower alkoxy benzoate or methyl 3-amirlo-4-halogeno benzoate with a higher aliphatic alcohol,"e.g.n-dodecyl alcohol, iso-tri-decyl alcohol and 2- ethyl hexyl alcohol.

'Among the couplers represented by the Formula I, those in which R is astraight-chain alkyl group are inferior in solubility in a high boilingsolvent and those in which R is a branched-chain alkyl group areconsiderably difficult to synthesize because the intermediate II whichis obtained in oily form and difficult to crystallize is still admixedwith a large amount of the starting higher alcohol and consequently thesubsequent condensation with ethyl 'benzoylacetate or isolation of thecondensation product becomes very diflicult.

Under the foregoing circumstances, we have found that a novel yellowcoupler of the Formula III as given hereinafter has good solubility in ahigh boiling solvent and is very useful as the protected type coupler R5(III) .(wherein X is hydrogen or halogen, Y is hydrogen, lower alkyl,lower alkoxy, aryloxy or halogen; R is tert. butyl,

(50 O (EH-430 0R3 R1 (IV) (wherein R R and Y have the same meanings asin the Formula III) with ethyl pivaloylacetate or a substituted orunsubstituted ethyl benzoylacetate. The above compound of the Formula IVis obtained by reacting 3-aminobenzoic acid or 3-amino-4-substitutedbenzoic acid with a 2-halogeno fatty acid ester. The starting materialsused for the preparation of the new couplers are available at low costas industrial grade products, and moreover, the preparation needs only 3to 4 steps. Accordingly, the couplers used in this invention areobtainable at a particularly low cost.

Solubility of the couplers used in this invention in a high boilingsolvent or organic ester solvent, for example, dibutyl phthalate,triphenyl phosphate, ethyl acetate, etc. is remarkably improved byvirtue of the introduction of an alkoxycarbonyl group at the a-positionof the alkyl group in the carboxylic acid ester, as shown by the FormulaIII. The couplers can accordingly be used as a stable solution of highconcentration and can be added to a photographic emulsion in asuflicient amount to form. a light-sensitive photographic materialyielding a dye image with high density.

In the Formula HI, where X is hydrogen and R R and R are the same,solubility of the couplers each having hydrogen, a lower alkyl group, alower alkoxy group, an aryloxy group or a halogen atom as thesubstituent Y varies according to the following order of solubility:

lower alkoxy hydrogen=lower a1l yl aryloxy=halogen For example,solubility of the coupler having a chlorine atom as Y is reduced to /3-/s of that of the coupler having a methoxy group as Y.

Solubility of the couplers can, however, be particularly increased, whenan alkyl group is introduced as R or a branched-chain alkyl group issubstituted for a straightchain alkyl group as R Conversion of thesubstituent may be efiected by using an agent selected depending onpurpose. For example, monochloroacetic acid, a-bromopropionic acid,a-bromo-n-butyric acid, a-bromoiso-butyric acid, wbromo-caprylic acid,oc-bI'OlIlO-lfilll'lC acid, etc. are used for converting R and laurylalcohol, 2-ethyl hexanol, 2-octyl alcohol, 7-ethyl-2-methylundecanol-4,di-isobutylcarbinol, etc. are used for the conversion of R These fattyacids and alcohols are all readily commercially available. Among therest, a-halogeno fatty acid esters can be synthesized in good yield andin such high purity that no admixture of starting material is observedin a crude product by reacting a-halogeno fatty acid with alcohol in anequivalent molar ratio. Further, the intermediate of a the Formula IVwhich is obtainable by the reaction of a substituted or unsubstitutedaminobenzoic acid with ochalogeno fatty acid ester in an equivalentmolar ratio is so pure that no admixture of starting material isobserved in the crude product, and there is not needed any complicatedisolation and purification steps. Because of such high purity of theintermediate (IV), the condensation with ,B-keto-ester proceeds smoothlyand thus a resulting condensation product is readily isolated. It istherefore evident from the foregoing that the couplers according to thisinvention can be prepared at a low cost and are particularly useful fromthe industrial viewpoint.

In addition to the above advantages, the couplers used in this inventionexhibit improved photographic properties. They can form a highly densedye image and are reduced in fogging and desensitization. Further, acolor photographic material which can yield a highly transparent colorimage can be obtained from the emulsion of this invention in which thecoupler is well dispersed because of its good solubility in high boilingsolvent. Dye image obtainable from the couplers used in the presentinvention has good spectral absorption characteristics and isparticularly fast to light, heat and humidity and does not suffer fromdiscoloring or fading caused by various chemicals. In particular, acoupler containing as R a tert. butyl group or o-substituted phenylgroup produces an outstandingly fast dye image. Further, it has beenfound that maximum absorption of dye image is shifted to a longwavelength region when the carbon chain of R in the Formula III islonger, as compared with the case where R is hydrogen or short-chainedalkyl group. For example, the couplers of the Formulas 6 and 7 as givenhereinafter show the maximum absorption at 450 m and 460 m respectively.This means that the preparation of a light-sensitive color photographicmaterial properly meeting selected purposes is possible when the properlength of the carbon chain of alkyl group contained as R is selected.

Typical couplers used in this invention are shown below by way ofexemplification only.

l oo GInOONH-Q C O O CH COOCuHi5(n) (m.p. 101-103" C.)

OCHa

C O O (EH-0000 6113301) (m.p. 78-79 O (I)! CO CHzCOHN -ooomo OHN l COOCH-CO O C4H (n) a nm) I (m.p. 96-97 C-) (8) (I) 0113 oo- COGH2COHNCOO(|3H-COOCi2 !a( (m.p. loo-102 o.)

on, CHzCfl omofliorhoimm 1 5 (m.p. -66 C.

Q0 0 outcome-Q J30 0 01120 O 0 0 21125 (n) (mp. 91-93 C.)

o o amount-Q co 0 onto 0 0 01,112.01

Q-COCHzCOHN-Q O0 CHQCOO 01211250 Cl CH3 CHa-(E-(JO CH2COHN 0O CHzCOO012112501) (m.p. 72-74" C.)

A light-sensitive color photographic material is prepared in thefollowing manner: A yellow coupler as shown above is dissolved in a highboiling solvent having a boiling point of C. or higher such as tricresylphosphate, dib-utyl phthalate, etc. or a low boiling solvent such asbutyl acetate, butyl propionate, etc. On occasion, the coupler may bedissolved in a mixture of these solvents. The resulting solution ismixed with an aqueous gelatine solution containing a surface activeagent. The mixture is emulsified in a high speed rotary mixer or colloidmill and then immediately added to a light-sensitive silver halidephotographic emulsion. The photographic emulsion thus obtained is coatedon a support such as a film base or baryta paper and dried to remove amajor part of the low boiling solvent. Alternatively, the emulsifiedmixture is set by cooling, extruded to noodle form and freed from lowboiling solvent by, for example, washing with water, and thereafteradded with warming to the photographic emulsion, which is then treatedin a similar manner as above to give a lightsensitive color photographicmaterial. The preparation of photographic materials is not limited tothe abovemethod but any other modification may be practicable.

The coupler is preferably added to the photographic emulsion in anamount of 10-100 g. per mol of a silver halide contained in theemulsion. The above range is not, however, critical. The photographicemulsion used in this invention may contain any silver salt such assilver chloride, silver iodide and silver bromoiodide. Further, theemulsion may be sensitized with a chemical sensitizer, for example,sulfur sensitizer, natural sensitizer found in gelatine, reducingsensitizer and noble metal salt sensitizer. Said photographic emulsionmay further contain photographic additives ordinarily used, such as anantifoggant, stabilizer, anti-stain agent, anti-irradiation agent,polymeric modifier, coating aid, etc. As the optical sensitizer used inthe photographic emulsion, any known carbocyanine dye or merocyanine dyemay be used. When the photographic emulsion having the spectralsensitivity in the same region is coated in double layers, the coupleraccording to the present invention may be included in either layer orboth layers.

The light-sensitive photographic material thus obtained is then exposedto radiation ray, X-ray visible ray, infrared ray, etc. and thereaftertreated with a developing agent principally comprising ap-phenylenediamine series developer. After bleaching and fixing, thereappears a yellow dye image of high density having good TABLE 1 Requireddibutyl M.P phthal- Formula C ate (ml.)

Novel coupler 01 88-89 2 O 0 CBC O O Cnll'za 4 Known coupler (cf. Cl98-100 Japanese Patent Publication N o. 5,582/1967) -C 0 01120 0 EN 0 012 15 Novel coupler Cl 72-74 0. 5

r CHa-(I1C 0 CHzC OHN- CH3 l C O O CHzO O O C|2H25 Known coupler (cf. Cl139-140 10 United States Patent CH 3,265,506) Q l 0115- 5-0 0 CH2C OHNspectral absorption characteristics and showing a maximum absorption at450-465 mg. Said dye image is also excellent in transparency andfastness to light, heat and humidity.

Typical developing agents used in this invention for the treatment ofthe light-sensitive photographic material are the sulfates, sulfites andhydrochlorides of the following compounds:

N,N-diethyl-p-phenylenediamine,

N-ethyl-N-fl-methanesulfonamidoethyl-3-methyl- 4-aminoaniline,

N-ethyl-N-hydroxyethyl-p-phenylenediamine,

N-ethyl-N-hydroxyethyl-2-methyl-pphenylenediamine, and

N ,N-diethyl-2-mcthyl-p-phenylenediamine.

The couplers used in this invention are compared with known couplershaving similar structural formulas in melting point and solubility inhigh boiling solvent. The solubility is determined by measuring anamount (ml.) of dibutyl phthalate required for completely dissolving 1g. of coupler at 60 C. The results are shown in Table l. I

As evident from the above Table 1, the novel couplers used in thisinvention melt at a lower temperature and have better solubility in ahigh boiling solvent as compared with known couplers and therefore itwill be understood that such new couplers are very useful as protectedtype couplers.

The present invention will be explained in detail by the followingexamples which are given by way of illustration only and do not intendto limit the scope of the invention thereto.

EXAMPLE 1 20 g. of the present coupler (3) is dissolved at 80 C. in amixture of 20 ml. of dibutyl phthalate and 60 ml. of butyl acetate. Theresulting solution is mixed with 10 ml. of an aqueous solution of 10%Alkanol B (alkyl naphthalene sulfonate produced by Du Pont, USA.) and200 ml. of an aqueous 5% gelatine solution. The resulting mixture istreated in a colloid mill. The coupler dispersion obtained is added to 1kg. of a high speed gelatino-silver iodobromide photographic emulsion,which is then coated on a film base and dried.

The light-sensitive photographic material thus obtained is exposed tolight in the ordinary manner and then treated at 20 C. for 10 minuteswith a developing solution of the following formulation:

G. N,N-diethyl-p-phenylenediamine hydrochloride 2.5 Anhydrous sodiumsulfite 2.0 Sodium carbonate monohydrate 82.0 Potassium bromide 2.0Water to make up 1000 ml.

The developed film is subjected to ordinary stopping and fixing andthen, after washing with Water for l-l5 minutes, treated for minuteswith a bleaching bath of the following formulation:

G. (Potassium ferricyanide 100- Potassium bromide 50 Water to make up1000 ml.

The film is washed with water for 5 minutes and further treated for 5minutes in a. fixing bath of the following formulation:

G. Sodium thiosulfate pentahydrate 250 Water to make up 1000 ml. Thefilm is washed with water for 20-25 minutes and dried. A brilliantyellow dye image having a maximum absorption at 455 my. is obtained.

8 EXAMPLE 2 10 g. of the present coupler (13) is dissolved at 60 C. in amixture of 10 ml. of tricresyl phosphate and 30 ml. of butyl acetate.The resulting solution is mixed with 5 ml. of an aqueous solution of 10%Alkanol B and 200 ml. of an aqueous solution of 5% gelatine. The mixtureis treated in a colloid mill. The resulting dispersion is added to 500g. of a gelatino-silver iodobromide emulsion, which is then coated on afilm base and dried.

The photographic material thus obtained is exposed to light and treatedat 20 C. for 10 minutes with a developing solution of the followingformulation:

G. Metol 3.0 Anhydrous sodium sulfite 60.0 Hydroquinone 6.0 Anhydroussodium carbonate 50.0 Potassium bromide 1.0

Water to make up 1000 ml.

After being subjected to ordinary stopping, hardening and water-washingsteps, the material is exposed to white light and then treated at 20 C.for 12 minutes with a developing solution of the following formulation:

G. N,N-diethyl-p-phenylenediamine hydrochloride 5.0 Anhydrous sodiumsulfite 2.0 Sodium carbonate (monohydrate) 82.0 Potassium bromide 1.0

Water to make up 1000 ml.

The developed material is further subjected to stopping, fixing, waterwashing and bleaching steps and washed for 20 minutes with running waterand dried. A yellow dye image having good transparency and showing amaximum absorption at 450 Ill/I. is obtained.

EXAMPLE 3 10 g. of the present coupler (6) is dissolved at 50 C. in 20ml. of dibutyl phthalate. The resulting solution is mixed with 5 ml. ofan aqueous solution of 10% Alkanol B and 200 ml. of an aaqueous 5%gelatine solution. The mixture is passed through a colloid mill severaltimes to form a dispersion. The resulting dispersion is added to 500 gofa gelatine-silver chlorobromide emulsion, which is then coated on abaryta paper and dried.

The light-sensitive photographic material thus formed is exposed tolight andthen treated at 20 C. for 10 minutes with a developing solutionof the following formulation:

G. N-ethyl N-hydroxyethyl-p-phenylene diamine sulfate 2.5 Anhydroussodium sulfite 2.0 Hydroxylamine hydrochloride 1.0 Sodium carbonate(monohydrate) 82.0 Potassium bromide 2.0 Water to make up 1000 ml.

G. Ethylenediaminetetraacetic acid disoduim salt 40.0 Ferric chloride30.0 Sodium carbonate (monohydrate) 20.0 Potassium bromide 30.0

Sodium thiosulfate (pentahydrate) 200.0 Water to make up 1000 ml.

The material is washed with water for 20 minutes and then treated for 2minutes in a stabilizing bath and dried.

9 A yellow dye image having a maximum absorption at 450 m is obtained.This image is excellent in fastness to light and heat as well as instorability.

When the present coupler (7) is used in a similar manner as above inplace of the coupler (6), a yellow dye image having the maximumabsorption at 460 m and excellent in fastness to light and heat as wellas in storability is obtained.

EXAMPLE 4 2.0 g. of the present coupler (12) is dissolved in 5 ml. ofbutyl acetate. The resulting solution is mixed with 1.5 ml. of anaqueous solution of Alkanol B and 20 ml. of an aqueous 5% gelatinesolution and the mixture is treated in a mill.

The coupler dispersion thus obtained is added to 100 g. of a bluelight-sensitive high speed gelatino-silver bromoiodide emulsion, whichis then coated on a film base and dried.

The light-sensitive photographic material thus obtained is then exposedto light and treated with the developing solution as used in Example 1.A brilliant yellow dye image having a maximum absorption at 460 m isobtained.

What We claim is:

1. A light-sensitive silver halide color photographic emulsioncharacterized by inclusion of a yellow coupler of the general formulam-ooorro OHN OCH;

Q-ooomoorm-Q C O O (DH-{3 O OC1uHaa(n) (m.p. 78-79C.)

3. A light-sensitive silver halide color photographic emulsion asclaimed in claim 1, wherein said yellow coupler is one having thefollowing formula 01 -ooomo ours-Q l o 00011.0 0 0 CHzCHC4Ho(n) (m.p.97-98C.)

4. A light-sensitive silver halide color photographic emulsion asclaimed in claim 1, wherein said yellow coupler is one having thefollowing formula O O OCHC O OCnHnOD (m.p. 88-89C.) 5. A light-sensitivesilver halide color photographic emulsion as claimed in claim 1, whereinsaid yellow coupler is one having the following formula OCHa Cl C OCHzCOHN oooHro 0 0o 12H25(l1) (m.p. 99-103C.) 6. A light-sensitive silverhalide color photographic emulsion as claimed in claim 1, wherein saidyellow coupler is one having the following formula CH: CHr-i-COCHzCOHNQReferences Cited UNITED STATES PATENTS 3,551,155 12/1970 Yoshida et al96100 J. TRAVIS BROWN, Primary Examiner US. Cl. X.R. 9655

